The right conditions are crucial for the successful storage of any crop, and the produce itself needs to be in perfect condition – no blemishes, or breaks in the skin. It is easy to bruise fruit and veg as you harvest them, and once they are no longer growing they have no means to heal.
Different crops, such as root crops, potatoes, alliums, beans, cabbages, leeks, tomatoes and pumpkins, all need different storage conditions. You can also freeze many fruit and vegetables.
‘Root’ crops (except potatoes)
i.e. Carrots, parsnips, beetroot, turnip, swede, kohlrabi, and celeriac
Interestingly, these roots are the storage organs of biennial plants, and therefore - in the right conditions – they store naturally and easily. Harvest carefully, taking care to avoid skin damage. Remove excess soil, but do not wash or scrub as this may damage the skin. Remove leaves by twisting off close to the crown. Place in shallow crates/boxes separating layers with slightly damp packing material such as leaf mould, sand, sieved soil, sawdust (from untreated wood only), and coir.
Keep very cool from 0 - 4°C.
Require slightly different conditions from ‘root’ crops. They must be kept dry and dark to prevent them from turning green – which is when they develop high levels of solanine, a toxic alkaloid. Harvest in dry, cool conditions if possible, and leave exposed to dry for a few hours. Remove any damaged tubers; store good ones in thick paper sacks closed at the neck to conserve moisture. Do not use plastic sacks - the humidity will be too high, which stimulates sprouting. Protect from low or freezing temperatures and store at 5°- 10°C.
Alliums – onions, shallots, and garlic
Harvest onions and shallots when all the leaves have fallen over naturally. Dig out garlic when just the first 4 or 6 leaves turn yellow. Keep in a hot dry place for a few weeks (if the weather is fine, they can stay outside resting above the ground.) Bulbs are ready to store when skins are dry and papery. Plait into ropes or hang in net sacks which allow the air to circulate freely. Protect from freezing, ideal temp 2 - 4°C.
French and runner beans
If you can’t keep up with the harvest, either freeze or leave some pods to set the seed. When the pods are dry, shell out the dry beans and store them in a paper bag.
Firm red and white winter cabbage will store for several months if harvested before the first frost. Leave roots intact or at least 15 cm of stem. Place on slatted shelves, covered with straw or thick layers of newspaper if temperatures drop. Ideal temp 0 - 4°C.
Leeks and Brussels sprouts
Both can normally be left in the ground over winter. However, if extremely bad weather is forecast you can bring a few indoors for immediate use. Dig up entire plants, with roots, and place them in a bucket with just enough water to cover the roots. In a cool place, they will stay fresh for up to a week.
Pick green tomatoes before the first frost – ripen either by hanging the whole vine in a cool dry place or by wrapping individual fruit in paper and storing them in trays. You can hasten the ripening by putting them in a closed bag or box with a ripe apple or banana.
Pumpkins and winter squashes
Pumpkins and squashes need a few weeks of the sun towards the end of the growing season to develop tough skin for storage. Harvest before the first frost. Cut with a long stalk, with part of the vine attached – this will protect the stem from rotting. Stored cool and dry with plenty of air circulation they can last 6 – 9 months. Ideal temp 10 - 15°C.
Vegetables such as cauliflower, broccoli, peas and beans, and leeks can be frozen to help store during a glut. It is best to blanch in boiling water first and to freeze in manageable quantities. Tomatoes are best cooked into a sauce before freezing.